I got 577 marks in neet 2019. Uttar Pradesh. Is it wise to drop since it was my first attempt?

As per the previous year he has very good chances to get into up medical colleges government .last year the maximum cutoff was 589 and minimum of 469 in the MBBS government college of up.So with this marks you have chances of getting into almost all the government MBBS colleges except for King George's Medical University, Lucknow whose cutoff was 589. If your AIR is within 10000 then you will get colleges here.
However trends change every year based on question difficulty, number of students applied etc .Check the site and see whether your rank is coming within the closing ranks of the colleges. If not you may give a drop since you have already got such high marks.
https://medicine.careers360.com/articles/neet-cutoff-up

Uttar Pradesh NEET Cut offs 2018:
UR: 469
OBC: 429
SC: 372
ST: 182
You can get a seat in almost in every Government Medical College of UP except for King George Medical College and Ganesh Shankar Vidyarthi Medical College for UR Category. And if you belong to Reserved categories, you can get a seat in almost every Government Medical College without exceptions.  Your marks are that good. If you do not want to take a seat and then prepare well for next yeat, it is your call. But cut offs change every year and next year they will be still higher and even if you score the same marks, your chances will reduce. So you should be able to score more than your current score.

Hello Anand !!

In 2018 the cut off of government medical college in Uttar Pradesh through state quota was -
UR-469
OBC-429
SC-372
ST-169
This year the cut off is expected to increase by 20-30 marks .

With your marks of 577 ,regardless of the category you will be getting a seat in UP easily  . Therefore there is no question of taking a drop even if you are not getting into the top college for MBBS.
All the best.
Hope this helps .